Braided product and method for producing the same



Jan. 10, 1950 N. c. JECKEL 2,494,389

BRAIDED PRODUCT AND METHOD FOR PRODUCING THE SAME Filed June 22, 1946 4 Sheets-Sheet l g ag!) l 40 Q 10 4/ INVENTOR flarmazz t. 120%! v ATTORNEY Jan. 10, 1950 N. c JECKEL 2,494,389

BRAIDED PRODUCT AND METHOD FOR PRODUCING THE SAME Filed June 22, 1946 4 Sheets-Sheet 2 ink INVENTUR Akrman f JZc/fzl BY a j ATTORNE N. C. JECKEL Jan. 10, 1950 BRAIDED PRODUCT AND METHOD FOR PRODUCING THE SAME 4 Shets-Sheec 3 Filed June 22, 1946 INVENTOR Afar/nan (f fer/ d ATTORNEY N. c. JECKEL 2,49%389 BRAIDED PRODUCT AND METHOD FOR PRODUCING THE SAME Jan. 10, 1950 4 Sheets-Sheet 4 Filed June 22, 1946 INVENTOR.

Patented Jan. 10, 1950 OFFICE BRAIDED PRODUCT AND METHOD FOR PRODUCING THE SAME Norman C. Jeckel, Glens Falls, N. Y. H Application June 22, 1946, Serial No. 678,595

Claims.

The present invention relates to the art of braiding tubular products and more particularly to an improved braided tubular product and to the method and the machine for braiding such improved tubular product in which the diameter of the tube changes along its length.

While the invention is of general applicability in the braiding of tubular products which change in diameter either slowly over a considerable extent of their length or which change their diameter in a step-like manner without having a taper of any appreciable extent lengthwise of the product, it has been developed in connection with the production of braided tubes employed in the manufacture of catheters, bougies, and similar surgical instruments and for this reason these products are referred to particularly in a detailed disclosure of the invention. It will be appreciated that the improved method and machine are not confined in their application to the manufacture of these particular products.

In the braiding of catheter tubes it is necessary that the braided product be formed with a smooth and uniform taper. Such a taper has been secured heretofore by braiding the tube over a mandrel which is appropriately tapered to give the braided tube the taper which is desired in the final product. This method produces a product in which the number of threads and the diameter of each individual thread remains uniform throughout the extent of the product. Since this is so, the tightness of the mesh must be varied to secure the change in the diameter of the tube conforming to the mandrel taper. As the instruments in use are subjected to endwise tension and compression as well as to transverse bending looseness in the mesh, this being the condition of the larger straight cylindrical portion of the tube, very much increases the hazard of rupture of the coating carried on the fabric when the instrument is in use. Looseness of mesh at some point is unavoidable with the mandrel method referred to.

Another method which has been proposed for producing a tapered tubular braided product involves the substitution as the braiding operation proceeds of heavier or lighter threads, that is, threads of less or greater count. This method very much increases the machine attendants time required for removing and replacing the bobbins and for tying ends, as well as a more skillful attention to the machine by the attendant to prevent defects. It also involves considerable machine stoppage over a period of time to make quires that a large number of bobbins carrying yarns or threads of different size or count shall be available for eifecting the requisite substitutions.

Satisfactory catheter tubes can be made by the methods and machines disclosed in my prior Patents Nos. 2,354,212 and 2,388,693, these methods involving the removal of bobbin carriers from and return of bobbin carriers to the sinusoidal paths in which they travel about the axis of the completed product so that the number of threads which enter into the braiding operation may be increasedor decreased to correspondingly change the diameter of the braided product. These methods result in a tube in which the tightness of mesh along the length of the taper is substantially uniform and also one in which the tightness of the mesh in the tapered part of the tube may be kept the same as the mesh tightness in adjoining cylindrical portions of the tube. However, the removal of a bobbin carrier and the consequent withholding of its thread from the braiding operation results in a disturbance of the braided pattern. If the braided pattern in the cylindrical portion, for example, is the conven- 1 tional over 2, under 2 in which each thread possible the necessary changes. Moreover, it repasses over two other threads, under two other threads, and again over two other threads, removal of a bobbin carrier to withhold a thread from the braiding operation will disturb this pattern. The pattern as a result of such withholding of threads from the braiding operation, for example, may become one where a thread may go under 1, over 2, under 2, over 2, under 2, over 1,

-' .etc. Disturbance of the braided pattern can be minimized in the methods of my prior patents and the effects thereof made negligible by carefully predetermining the total number of bobbins, the number of bobbins to be removed to secure the total taper and the particular bobbins to be removed and the order of their removal. In making any such predetermination there are certain limits that must be observed if a smooth braided tube is to be obtained. There is, in fact, a limit to the total number of threads which can be withheld and still have the braided product remain circular or tubular.

It is an object of the invention to produce a tubular product in which a portion of the length thereof is reduced in diameter with respect to an adjacent portion and in which the braided pattern may be maintained in both of these portions of the length of the tube.

It is another object of the invention to provide a tubular product having a tapered portion, the

braided pattern being uniform and the mesh of such pattern being uniformly tightly braided.

An additional object is to provide such a tubular product, which may be of varying diameter, in which the characteristics of the threads of the braid are changed in such a manner as to be equivalent to reduction or increase in the size or count, that is, the weight of such threads per unit of length,' or;t change the composition of these threads.

A further object of the invention is to provide a braided tubular product in which, whether tapered or of uniform diameter the threads comprise different materials in difierent sections of the length thereof.

Another object of the invention is to provide methods of producing braidedtubular-products having these characteristics.

It is a still further object of the invention to provide a machine which will carry out these methods of -;producing ,such a braided :tubular produ t- ..Iihave foundythata tapered braided tubular product which is substantially uniformly tight in meshand of aunfierm braided pattern both in theiqyljndrical portions of the tube as well as in thetaperedportionsthereof may be produced by having-at-least someof the-threads which enter intothabraidinsoperation made up of a plurality ofindependent, strands. Thus, a given thread mayiconsist of two, three, four or even more separate-strands. Thesestrands are not twisted togetherto-iormthe thread. 'Allof them, however, are fed-together as agroup into the braid asiif itheywere. a singlethread delivered from the samepoint on the serpentine or sinusoidal path over .which in the ordinarybraiding operation the bobbin carrierstravel. These strands, therefore,;lie more or-less parallelzto each other in the thread in :the rbraided pattern of the tubular product of .the invention.

It isa well known practice'in certain textile operations. simultaneously to feed a number of yarns or strands of yarn and to wind these strands together-upona bobbin in more or less parallelirelation :without'twisting them together asordinarilyisdone'formaking a plied yarn or thread. Thenumberof strands thus wound upon the bobbin-is referredto as one, two, three armors-ends up on the bobbin, one strand of yarn thus wound being known as one end up, two strandstwoendsup etc. Bobbins so wound withmore than oneend up, if desired, maybe usedin the method-of braiding tubular articles as is disclosed in my prior-patents above referred to. Removalof-such a bobbin, however, to withbold athread from the braid as disclosed in these patents would, of course, withhold all of the strands-of yarnwound 'on such a bobbin. The disturbance of the braided pattern above mentioned,therefore, would not-beavoided by such a practice.

In accordance with the present invention, 'I provide the-bobbin carrier, which as in the usual tube -braiding-machineis adapted to travel in one of-two intersecting serpentine or sinuous paths about,a central space, with a. plurality of bobbin holders instead of a single holder. At leastone, andif desired morethan one or all, of these holdersis remmably supported on the carrier or at leastoneof theholders may be .fixedin the carrier to maintain at least the strand ofthe-bobbin mountedthereonjor continuous feeding into the braiding .operation while ;the other holdersare the braiding in this manner but is constructed constructions.

rso-that all or certain of the bobbin carriers are adapted tosupport a plurality of bobbin holders instead of a single bobbin holder as in the prior These bobbin carriers are spaced along the respective intersecting sinuous paths, similarly to the arrangement of the carriers in the conventional machine. The means for guiding the carriers in the sinuous paths and the driving mechanism and the various other parts; associated therewith for driving the carriers, as well-as the carriers-themselves, are so constructedand coordinated, however, that the bobbin carriers .moving in one sinuous path, as well as the plurality 'of bobbins-supported thereon, do not :interfere with eachother .or -;with the carriers or the bobbins moving-m the. other-sinuous path. Nevertheless, the machine of theinvention .is ,capable of producing a braided tubular productof the same braided pattern in the cylindrical; portions, and of: the same size,. taper, tightness. of meshand. other characteristics as is produced; by the machine:- disclcsed in my prior 1 patents. The necessary crossing ,of-the threads from one set=ofibobbins in onepath over those from the set of bobbins inthe other-path is accomplished to carry: out .the braiding action in such a ivay that-all the strands ofgeach thread are passedoverall ofthe strands-of the other threads. Individual strands of agselected thread orthreads, however, may be withheld by removing from the carrier the-bobbin p1 bobbins on which such strandiis wound while leaving ,atleast one bobbin on this carrier-tosupplydts strandto the braided pattern.

;-Eachof the bobbinswhich' is carried by oneo'f the ,plurality of bobbinv holders supported on a bobbin carrier mawhave rwoundtthereon a single strand of yarnotsuitabletype, either single or p y n, with-such an amountof twist therein-asis nitable for handling the yarn and for the ;I ,O l1l0t-:t0ibemad e. Each such bobbin, however, if desired, mayhave wound thereon a plurality. of fen s 111 as .above', defined. Within the scope of the1invention the .strand of yarn, or the ends. which make upthestrand, which is wound on a-n-i individual bobbin :to be mounted on 0 ne; of the vplurality of bobbin holders on a carrier may he ofadifierent characteristics, as to fib r, sizatwist, colorskind-of materialand other charaet ri ticsin orderto securepeculiar qualities in the product, as hereafter described. It isimporta-nt, however, in allsuchvariationsthat the :two or more strands of yarn of whatever tha acteristics extending from their respective bobbins ongaicarrierzto mebraiding point are not twisted or crossed-over each other'to any appreciable degree. but substantially are maintained as separate ,and individual strands throughout their associationzwith thebraiding operation, so that eitherof them may be withheld from'this operation-whena.change.is desired.

zsnch azstrand wound on a bobbin, whether one-ormoretends-upfi forms with the similar strand or strands on the other bobbin or bobbins which are carried by the same bobbin carrier the thread which is to be braided into the braided pattern. All of the strands from the several bob bins of a given bobbin carrier, therefore, are fed into the braiding operation from adjacent the same point, that is the position at any moment of the given carrier in the serpentine path, and together they make up a single thread in the completed brain which, for example, may be laid over 1, under 1, over 1, etc., or over 2, under 2, over 2, etc., or in any other predetermined pattern determined by the design and adjustment of the braiding machine.

In order to avoid twisting together of the strands leading from the two or more bobbins on the same carrier, thus to insure their being fed into the braided pattern as individual strands available to be withheld from the braided pattern and returned thereto to secure changes in the diameter of the tubular product, it is important that the bobbin on a carrier not be permitted to revolve about each other or about any axis which moves along the serpentine path or parallel thereto or which moves otherwise about the central axis. To this end the invention provides means for guiding each carrier along the serpentine paths in which it moves substantially in a constant average angular relation to the direction along or tangent to that path. The carrier is thereby prevented from rotating on any axis passing through or adjacent to or outside itself other than the axis of the orbits of the endless serpentine paths. Thus, the carrier, so to speak, always faces the axis of these orbits as it revolves about this central axis. Except for the oscillation of the carrier and of the plurality of bobbins carried thereby toward one side and the other of the path in which they move, and which necessarily is caused by the changes in the direction of the serpentine or sinuous paths, the carrier and its bobbins as they move are held in a fixed relation to the line of the path and to the radius from the central axis to the carrier.

When it is desired to change the diameter of the braided tube, for example, to decrease the diameter, one or more of the movable bobbin holders may be removed from one or more bobbin carriers so as to withhold from the braided pattern a strand wound on the removed bobbin but not the whole thread which is composed of this withheld strand and at least one other such strand. The thread is now made up of a fewer number of strands. A strand in this way may be withheld from a single thread at a time or a plurality of strands respectively of threads entering the braid at diiferent points circumferentlally related to each other may be withheld at the same time. Such strands from a plurality of different threads may be withheld in succession so as to distribute the withheld strands about the circumference of the tube and lengthwise along the tapered portion thereof. The points at which the withheld strands become excluded from the pattern, that is, pass out at the surface of the tapered portion or enter the tubular space within the tubular product in the manner disclosed for the threads in my prior patents above referred to, therefore, may be distributed in the portion or portions of reduced diameter in any way convenient or suitable for securing the desired form or tape. In all such variations of the manner in which the strands are withheld from the braiding operation so as not to enter into the braiding pattern, at least one of the strands from a bobbin carriediniti'ally by the same bobbin carrier is retained in the braided pattern and is fed to the point at which the braiding operation is eifected from the carrier on which initially both bobbins are mounted. Reduction in the diameter, there-g fore, may be secured in any, desired practical way by selection of the strands to be withheld and selective removal of .their bobbins from carriers 'moval and the number of bobbins removed and the number of bobbins remaining on each carrier may be varied and may be determined within the skill of the art to secure variation in the angle 3 or shape of the taper as well as the total desired reduction in diameter of the tube.

The objects and features of the invention will be more fully described in connection with the drawings and certain mechanical features of the machine utilized to carry out the braiding operation which constitute improvements upon the braiding machines ordinarily used for the production of tubular products will become apparent from such description.

Fig. 1 is a plan view of a braiding machine constructed for carrying out the method of the in-.

vention.

Fig. 2 is a perspective view of the braiding machine illustrating the manner in which the diameter of the tubular product is modified.

Fig. 3 is a vertical elevation of a bobbin carrier with a plurality of bobbin holders supported thereon, certain parts being shown broken away and in section.

Fig. 4 is an end elevation of the carrier and holders shown in Fig. 3.

Fig. 5 is a fragmentary section taken on line 55 of Fig. 3.

Fig. 6 is a view to enlarged scale of a tubular product having tapered portions and showing certain strands withheld interiorly and others withheld exteriorly of the product.

Fig. 7 is another View of the product of the invention showing the unbraided strands withheld exteriorly of the product.

Fig. 8 shows a pattern of the braided product.

Figs. 9 to 13 inclusive are diagrammatic representations of threads composed of a plurality of strands from which certain strands are withheld or are caused to enter the thread so as to enter the braided pattern therewith.

In the embodiment of the invention shown in Fig. 1, the braiding machine like those of my prior patents above referred to, is provided with a platen 2 of annular form about the central braiding axis 3. In this platen is formed a pair of sinuous grooves 4 and 6 intersecting each other and both extending about the central axis 3 to provide intersecting endless serpentine or sinuous paths along which the bobbins are moved. In each groove a foot member 8, as shown in Figs. 3 and 4, which is formed at the underside of the bobbin carrier In or is fastened thereto by suitable means is arranged to move lengthwise of the groove. As shown in Fig. 5, the foot member 8 is of generally ellipticalrshapeiin order itocaflord clearance as this foot member; together with :the carrier I 0, moves along the groove and Lpasses around the curves thereof. "The shape' ofiitheioot member-'3 is such -that while the carrier 1 t0: may

swivel-'onthe vertical axis l l which Lpa'sses centrally-through the carrier andathe footmemberzil, it cannot rotate a full turn or through a large angle upon this-axis. Theilengthwise extentaof the foot member aswell as 'of the carrier thusiare maintained generally parallel to the .1 lengthwise extent of the groove along which the1carrier2and its foot: member are moved as may beseen from Figi 1. Although the carrier: In supporting iauplurality of bobbins may angularly osciilateoa'bcut. its vertical axis t I Ito one side 1 or the'other of :the path in which' it moves, it always isretainedwith the same side thereoi substantially facing :the axis 3 of I the branding operation whichzproduces the tubular product. Twisting itogether 50f ithe plurality-of strands which are to-rcompose :each thread of thenormal braided pattern thus is' prevented.

order :to moveithe "carrier I I0 and its lfoot memberil along the groove in which itLis placed, as just described, the :carrieris: provided with a base: pin I L2 integral with or suitably fastened "to the foot member 8 and extending beneath the platen 2 into engagement with suitable *drivin'g member M- rotatable: on an. axis l 52and-driveneby gear Win the manner shown in my:priorJPatent No.2,354j212or by anysuitable meansisuchaasare utilizedin conventionalibraiding machines. The driving mechanism representedi'by the member l l -and the gear l-fi may be constructed-within. the

skill: of the art't'omove theseveral carriers taking into consideration the requisite length of :these carriers -so-that they will clearieachmther and sothat the bobbins carried therebyuwillaproperly effect the necessary crossingofvthethreads without mechanicalzinterference ofthe bobbins with each other or with :the carriers :as they move along the grooves andihaving-regardto the oscillating movement thereof above referredito.

To provide for support of a plurality ofbobbins each carrier It has formed thereinaplurality of holes -I' 8 the axes: of which are vertical to receive respectively the base pinszfi of the bobbin holders 2| 'Each bobbin holder is constructed with abase member 22 of Lbeam section supporting: a tubular spindle 24 which Y carries a bobbin :support '26. This bobbin supportmay be made of a-Wire or suitable-size having its ends "zi-extending about the-spindle 24 in spaced relationverticallyalong this spindle to position thebobbin ZB-at the proper distance from the-upperend of thespindleil and in suitable relation to the'thread guides 29, and-3i which are provided'in the thread guide support 32 which is-suitably' fastened atits lower end upon'the' bobbinholder base 22. In theparticular design of thebobbin holder, as shown in Fig. 3, withinthe hcillowspindleZ-d a Weight 3-3 is provided which is sli'dable within the hollow spindle. This weight carries an eyeletH-through whichis passedthestrand'35-from the bobbin 2 8 after this-strand is threadedthrough the thread guides 29 -3 U and 3 I. The requisite tension onthe strand 35 being delivered to the point of braiding from-the-eyelet '38 positioned'in-the upper end of the spindle 24 is secured in consideration of the friction provided by the bobbin support 2fi=and the weight of thetension weight BS a-s-the strand is pulled from -the bobbin. .As each o'f'the bobbins 28 which is carried on its bobbin holder 21 sup ported b :the ='carrier i0 is :provided with :such

8 tensioning means each of th-e strands entering the: braiding operation isheld under the requisite tension throughout the movement of the bobbin carrier and the-bobbins carried thereby-in'the endless serpentine path which extends about the central: axis 3 of the: braiding operation.

In order to prevent rotation-0f the bobbin holders 2| relative to: the bobbin carrier 19, Where, as-is usual, it 'is desired to prevent incidental twisting. of the strand 35 in the length-thereof which extendsbetween the spindle-24 and the braiding axis, spring clips (i'l are fastened at the ends or: the bobbin carrier it by suitable fasteners 36. These clips 31 engage'the lower flanges of the bases 22 of the bobbin holders. These lower flanges are provided with a straight edge 39 againstwhich the clips'3l may bear to prevent turning movementof the base 22 and therefore or the spindle 2 4.

s It will be apparent from consideration of Figs. 1-to '5,-inclusive, and the above description of the construction of the bobbin carrier (=0 and the parts supported thereby that, as each carrier moves along the groove to which it is assigned andby virtue of the intersecting arrangement of the sinuous grooves extending as endless paths about the central braiding axis 3, the braiding operation is effected with a plurality of strands 35"forniing each thread which enters the braided pattern. Thus in Fig.1 the bobbin carrier lfl supporting two bobbins dl is in-position relative to thebobbin carrier i2 supporting bobbins 43 so as to cross two strands from the bobbins l over the two strands from thebobbins 43 when, as shown by the arrows in Fig. 1, the carrier 42 is moving downwardly in the figure along the inwardly positioned portion of groove 6 at this place and under the strands 35 which extend from the bobbins'l carried by the carrier 45 which is moving upwardly along its groove 4 outwardly positioned atthis pointwith respect to groove ii. As shown in'the'upper part of Fig. 1, since all of the carriers"! B supporta plurality of bobbins, that is two bobbins each inthis embodiment-and with the number and spacing of the carriers ineach groove as shown, namely sixteen carriers'foreach groove composed of eight crests and eight valleys, the braided pattern will be formed, as shown in Fig. 8,'of threads each of which is composed of two strands 35,-each thread of two strands passing under two similar cross threads having two strands 35 and then over such two succeeding cross threads and then again under two such cross threads. Within the skill of the art a different pattern maybe produced by suitably forming and arranging the intersecting serpentine grooves and providing a different number of bobbin carriers in relation to the number of crests and valleys and spaced "suitably along these grooves. In the embodiment illustrated at least one of the two strands 35 from a carrier Ill always is led to the braiding operation at the central axis 3 and a cylindrical product having a uniform braided pattern may be secured aslong as such strands con tinue to be led to the braiding operation. The tension on-each strand '35 may be uniform as determinedby the weights33and the uniform method of :threading through the eyelets 29, 30, 3| and 33. To vary thediameter of the tube or to-produce a taper therein, however, whilem'aintaining the uniform pattern, individual bobbin holders 2 l areremoved from or replaced upon the carriers l0 while maintaining others of these holders on :the respective carriers. The -.tension on the strands, therefore, is maintained the same in either portion of the bobbins. I

Provision is made in the apparatus of the invention, similar to that disclosed in my Patent No. 2,388,693, for support of bobbin holders 2| and the bobbins thereon which are removed from the bobbin carriers In as they move along their respective grooves. For this purpose exteriorly of the sinuous paths 4 and 6 and suitably supported upon the platen 2 are provided a plurality of tables 46 positioned circumferentially about the platen 2 and about the central axis 3. In the particular embodiment illustrated in Figs. 1 and 2, in each such table five holes 48 are formed of such size as to receive the base pins 20 of the bobbin holders 2|. It will be apparent that the operator of the machine may lift the bobbin holder from its position on the carrier by springing the clip 31 outwardly; the strand 35 still extending from the upper eyelet'38 to the braided product at the braiding axis 3. The bobbin holder 2| thus lifted may be moved outwardly of the machine and the base pin 26 thereof inserted in one of the holes 48 of an adjacent table. In Fig. 1 from the bobbin carrier 56, for example, a bobbin-holder and its bobbin 5| have been removed to the table 46 which is at the lower left hand diagonal of the figure. Similarly from the carrier 52 the bobbin holder and its bobbin 53 have been removed to this table in order that the strands 35 leading from these removed bobbins may be withheld from the braiding operation. As may be seen in Fig. 2, the removed bobbins 5| and 53 are so positioned when supported on the table 46 that their strands 35 are carried above the general cone of strands from the bobbins which are moving along the grooves. The strands 35 from these bobbins 5| and 53 thus removed leave the braided pattern exteriorly of the tubular product, as shown in the upper part of Fig. 2. Only a few of the bobbins thus removed are shown in Fig.2 in order to avoid confusion of the lines in the drawing and of the removed bobbins with those which remain on the moving carriers. The tapered product shown in Fig. 2, however, is intended to represent that it may be produced by progressively removing a sufiicient number of bobbins as the carriers move along their respective grooves about the central braiding axis 3 until a suflicient total number of strands have been removed progressively to change the diameter of the tube from that of the cylindrical portion thereof to that which is formed at the point of braiding when the last bobbin to be removed has been placed on the table 46.

When it is desired again to increase the diameter of the tubular product the bobbins which are removed may be replaced on the'respective carriers from which they were lifted and in the reverse order to that oftheir removal so that a continuous tubular product may be formed, as shown in Fig. 7, with the withheld strands again entering the braided pattern to produce a reverse taper. When it is desired to cut the continuous product into the units, such as the braided tubes with tapered portions which are suitable for catheters, the completed portions of the tube may be cut as on the line AA in Fig. 7.

The withheld strands of each piece which after such cutting extend outwardly of the tapered portion then may be cut off substantially at the surface of the tapered part of the tube, as shown in the lower part of Fig. 7.

In the embodiment of the invention illustrated in Figs. 1 and 2 within the central space of the platen 2 of annular form is positioned a table 66 which in this embodiment is of octagonal form. This table 60 is provided with a plurality of holes 62 positioned about the circumference thereof, these holes being of such diameter as to receive the base pin 20 of the bobbin holders which may be removed from the carriers I0. As shown in Figs. 1 and 2, for example, from the carriers 64 and 65 the bobbins 66 and 6! have been removed to the table 60 and supported thereon by insertion of the base pins 2|] of their holder in the holes 62 which are at the lower octagonal edge of the table 60 in Fig. 1. As may be seen in Fig. 2, these removed bobbins 66 and 61 thereby become positioned within the cone of the strands which extend from the bobbins as they move along the sinuous paths about the central braiding axis 3. The Strands 35 from the'bobbins 66 and 6'! therefore are withheld from the braiding operation inwardly of the braided pattern and thus become positioned within the tube as may be seen in the portion of the tube which is broken away in Fig. 6. These strands 35 which are thus withheld inwardly from the braiding operation, however, are continuous and may again enter the braided pattern when the bobbins 66 and 61 again are replaced on the respective bobbin carriers. The bobbins which are removed from the carriers and supported by the table 66 may be returned to their respective carriers in the reverse order to that of their removal thus to produce the reverse taper in the braided product.

It will be apparent, also, that bobbins may be lifted from the several carriers to withhold their respective strands from the braided pattern and may be removed both to the tables 46 and to the table 69 in order that certain of the strands will be withheld exteriorly of the tubular product and others interiorly thereof, as shown at the'lower portion of Fig. 6. This and other variations in the selection of the bobbins and of their support in their removed position may be practiced within the scope of the invention to secure variations in the diameter of the tubular product and variations in the rate of taper, generally in accordance with the disclosures in my prior Patents Nos. 2,354,212 and 2,388,693. In allcases, however, such removal of bobbins efi'ects the withholding of strands and not the whole thread composed of these strands.

It will be apparent from the above description that in the method of the present invention of producing a tapered product in order to maintain the braided pattern a plurality of bobbins each having wound thereon at least one strand are carried on each bobbin carrier but only part of these bobbins are removed at a time from each carrier in accordance with a selected or predetermined system or order of removal. Where a tapered product is desired a progressive order of removal of the bobbins from the successive carriers may be adopted as disclosed in my prior patents but this method is applied to the removal of theindividual bobbins carrying the individual strands from a plurality of such bobbins carried by each carrier. The amount of yarn which enters the braiding operation, therefore, is reduced. Such reduction, by suitable choice of the count or size of the strands, may be equivalent to a reduction of the weight of the threads entering the braided pattern which se-' cures a result equivalent to substituting a thread of different size or weight.

Although in the particular embodiment disll closed in thedrawings and above described-only two, bobbinsare; shownfor each carrier: 10, within the scope of the invention a greater numberof bobbins than two-may be: carried .oneacncarrier in order to produce particular constructions :of the braided product. Other-varsiations also may be made;v For example, the carriers. moving along one of: the serpentine pathsimay be providedwitha different number of'bobbin holders thanthoseimoving along the other serpentinepath in order that the -threads which extend from the carriersin-the one path shall have'a-difierent number of strands than those extending from the carriers of theother path; In this Way-either the size of the threads as: composed of the "strands may be difierent-or they may be of different character because composed-of strands-which are ofrdifierent size or kind" or other characteristics.- These and other variations both in the number of bobbins sup-.- ported'by each carrier andr-thearrangement. of these carriers having a different number-of bobbins along'their: respective sinuous paths may bemade:.to:produce;tubu1ar products of different character.,

It is anrimportant feature'of'the invention, however; that the tension which is: securedby the weight 133 and' the other co-acting parts as above: described is applied" to each individual strand'whichsgoes to make up a thread entering theebraided pattern. Variations in the tension thus securedmaybe made by varying thesize of the weight 33 or by the use of other suitable tensioningrmeans inorder that the tension of the strandas it enters the braidedpattern may be determined and, controlled. In some cases it :may be desirable to provide tension in one or more of the strands ofa given thread difierent from those of othenstrands of such thread. It will be appar ent-alsosthat-by such variations in thetension of theindividual strands the total tensionof the threaditselrwhich :they compose ma; be varied and controlled to secure the desired tightness ofthemesh' of the braided product. It will be apparent, too, thatthe tension of, the individual strands, Whether they enter the braiding-operation'topform'the tubular'product or'on the other hand are withheld from this braiding operation, may betkept constant and uniform or of predetermined tension to secure the-requisite -tights ness of the mesh of the braided product both in itsicylindrical portion and in its taper portion.

While in the above exposition of the invention the bobbinwcarriers have been described as each carryingaspluralitypf bobbin holders each having aibobbin mounted: thereon, upon each .of which bobbins -is.-wound'one of the plurality of strands which makeup a thread entering the braided pattern, itiisr within the scope ofthe invention tdsecure variation of the mesh of the braided product-by providingcertain carriers which support a plurality of bobbins each supplying a strand to compose :a thread-while others: of the carriers may-carry asinglebobbin from which a threadiisledito thebraiding. operation. Thissinglee. bobbin and its carrier maybe constructed and: arranged" in the manner described in my priorxPatentsNos; 2',354;212 andi2,388,693, and this bobbin may be manipulated astherein disclosed; The invention, therefore comprises within :its scope the withholding either outwardly orinwardly of the cone of-threads, as above described; of one-or more but not all of the individual strands which compose a thread of the: braided pattern while at the same time anaotherrtlireadmay: bBrWhOH-Y -withheldroutwardly or inwardly of the cone: of'threads; with-correspondingmodificatiorrof the braided pattern only as to such wholly withheld thread; Particularly where the individual strands--which compose the-respective threads are withheld in step by step or other: regularly progressive manner to secure'a progressive taper of the tubular product, it will be understood that certain threads advantageously-interspersed between'the "threads which have-strands--thereof;so withheld, may be'withheld each as a. whole. By controlling the tension bothofthe-strands and of'the threads so withheld from the braided pattern in the manner above described, therequisite;tightnessof mesh ofthe braided-product may be secured. The threads whichasa .whole are so withheld aswell as the strands so withheld may again enter the braided pattern to increase the diameter'of the tubular product.

It isito be understood that a braided product which is produced in the manner above described in which the bobbins carrying .the-threads-or the strands arevmoved in a plurality of intersecting serpentina paths. extending as orbits about a central-axis-to effect crossing and recrossi-ng of the threads to secure the braided pattern-inthe product is inherently a tubular product. Such a tubular product, by suitable design of the braiding; machine-and arrangement and control of 1 the threads entering into the braided pattern, may, have a substantial internal diameter with certain of'the threads; located at the inner wall surface-of the tube: A braided tubular product,

however,- may; have no appreciable internal diametenandmay beformed with threads located at the innerwall surface in contactsubstantial-ly at thezbraiding-gaxim In certain-products of the prior art within this central space-a core thread is positioned, being-lied withinthe product-at the central axisin the braiding operation. It will beapparentthat' in'the product of the present invention such a core thread-.may be included or those strandsor threads'which are withheld inwardly of the cone of threads may -c0nstitute such acore; The invention; therefore, includes all-such products in which the space within the braided walls-.of the tube is of substantial diameter'and those in which'this diameter is so reduced that-there is substantially no space, the braided threads being in contact with each other or with acore thread or threads.

It will be: understood further that, as each bobbin carrier l0 is constructedto support a pluzrality of bobbins, at least one'of the bobbins on each carrier or on selected carriers may carry a strand of a given material and another bobbin on the same carriermay carry a strand of a different material. When the bobbins of the given material are removed from the carrier, the

strandswhich they-contain thereby being with held from the braided pattern, not-only will the product be reduced in diameter but the composition of the bra-id with respect tothe two materials will be changed. It will, be apparent that if all ofrjthebobbinswhich are-mounted in the machinewhichcarry strands of the given material progressively or simultaneously .are'removed from their carriers the braided product will become one from -which strands1ofsaid material are excluded-and will be composed of the strands of the other material. It will be ,further apparent that in producing. a taper at one portion of the length of the tubular product all of the strands of .saidg-iven. material may become withheld, the

strands of the other material continuing to enter the braided pattern, while at another portion of the length of the tubular product all of the strands of said other material may become withheld, the strands of the given material in this portion of the length entering the braided pattern.

If, for example, in Fig. 1 one of the bobbins 28 on each carrier I were to contain yarn of nylon and the other were to contain cotton yarn, a braided product would be produced which, because of the arrangement and number of the bobbin carriers in the particular embodiment of the machine of Fig. 1, would have a braided pattern in which each thread would consist of two strands, as diagrammatically shown in Fig. 9, one strand H of nylon and one strand 13 of cotton. These threads would be laid in a pattern in which each thread would pass over 2, under 2, over 2, under 2, etc. It will be apparent also, that preferably progressively in a predetermined order if it is desired to produce a tapered product, all of the nylon bobbins, for example, may be removed to the tables 46 until only those containing cotton strands are left on the carrier.

consist entirely of cotton threads. In the structure of Fig. 9 using only two strands per thread these threads each will become constituted by the cotton strands 13 as shown at the upper part of this figure. As above explained the pattern of this tube of reduced diameter will be the same as the braided pattern Of the portion of larger diameter into which both nylon strands and cotton strands enter. Moreover, by progressive and gradual replacement on the carriers of the bobbins containing the withheld nylon strands, the diameter of the tube again may be increased until all of the nylon threads are restored and the product against consists of threads composed both of nylon and cotton strands. Conversely the cotton strands may be withheld from the threads by removing the bobbins which carry the cotton strands from the carriers as above described. It will be apparent that in this case the portion of reduced diameter may be composed entirely of nylon threads.

In another variation of the construction of the braided product some or all of the strands of the threads may be formed of a material having a specific property, for example, one which is opaque to X-ray or the strands may be impregnated with a material which is X-ray opaque or has other qualities requisite for clinical or other purposes. In order to provide resistance to water and to the body fluids, such as the urine, the material of one set of strands or of the other or both, may be chosen to suit the purpose. This material may be one, such as that disclosed in my prior Patent No. 2,285,980 of June 9, 1942, which is meltable to provide a smooth homo geneous mass of the material throughout the length of the tubular product, such as a catheter, or in certain parts thereof. Such a meltable material may be nylon, or other plastic or a metal.

When the tubular product is composed entirely, or in part, of strands of nylon, as above suggested, or of other meltable material, especially where the nylon strands compose the portion of reduced diameter, the tapered tip of the catheter, or similar product or such part Of the length thereof as is desired, may be heated as disclosed in the Patent No. 2,285,980 to produce a sufiicient- 1y fluid condition of the nylon to allow the material of the strands to flow or knit together...

The a braided tube of reduced diameter, therefore, will Thereafter the material is allowed to" set. A catheter thus will be produced in which the tip may be of homogeneous character by virtue of the melting of the nylon and the balance of the length of the catheter may be of braided construction, which may include the nylon strands, and may have the requisite flexibility and strength resisting elongation and collapsing by virtue of the tight uniform mesh produced by the method herein disclosed.

In place of nylon or cotton strands or other materials ordinarily regarded as textile materials any material may be used which is susceptible to being made in the form of a flexible strand of substantial strength which may be wrapped on a bobbin from which it may be delivered, together with other strands, to form a thread for entering the braided pattern. Metallic strands or wire may be used for part or all of the strands, or for some or all of the threads making up the braided pattern. By the method of the invention products of particular characteristics thus may be produced. Wheremore than two strands contained in a thread are of diilerent materials, as shown in Fig. 10, it will be apparent that one of these strands may be withheld from the braided pattern by removing its bobbin from the carrier at one part of the length of the braided product and at another part of this length a strand of a second material may be withheld, the first strand at this portion entering the braided pattern, as shown in Fig. 10, or continuing to be withheld. One or the other of these strands in another part of the length may be returned to the braided pattern while a strand of a third material 15 is withheld. ,Moreover, selected strands 15 or selected threads containing at least one strand of a given material may extend throughout the length of the braided product, as shown in Fig. 11. Other variations and combinations may be made within the scope of the invention.

In another aspect of the invention the tubular product may be formed throughout its length with a substantially uniform braid and may be of cylindrical form, as are the products shown in Figs. 10 and 11, with portions of the length made of threads composed of strands which are all or for the most part of a given material or which contain a given material and with other portions of the length of the product composed of strands which are all or for the most part of a different material or which contain a diiferent material. In order to secure a tubular product which will be of substantially the same diameter in the several portions of the length thereof which thus are differently composed, it will be apparent from a consideration of the method above described, that when a bobbin is removed from its carrier, thereby tending to reduce the diameter, such reduction may be avoided or counteracted by replacing on the carrier a bobbin of a different material which previously has been removed from the carrier or has not yet been placed on the carrier to cause the strand to enter the braiding operation. It will be understood that, if such interchanging of the bobbins on all of the carriers were effected at one time between the bobbins containing strands of a given material and those which contain strands of a different material, the braided product would be formed with two adjacent sections of the same continuous braided pattern, each thread of the pattern containing the same number of strands in both sections. .The product may have the same di- .agegese as aameter the; two sectionsiiftthe size :and' other characteristics.of-theestrands of the two-sections -:are.-the sameor compatible. cwithin-the scope .of this aspect of-z the inventionuhowever, part of 1-16 -.bins to produce-.a-product inswhichradjacentseci tions thereof are of different materials. may be carried out, to efiect substitution of a wholethread composed of or comprisingone-material foraa the bobbins carriedbythe'carriers may be in- .5 vthread;compsed-.ofor comprising anotherma- 'terchanged vwithyothers carrying:.-a di-iferent ma- :teriaLawhile otherbobbins-are removed-from the carriers --.wi'thout such interchange tor are replaced. upon .the carriers :without removal of a terial. In order-toaccomplish this substitution of the full thread as compared with the substitu- ;.tion ofone strand of a thread for another strand thereof, it-is .=necessary to remove the bobbin Corresponding bobbin fr0m=- he c i Thue he 1-10 -Wh-ich-carries the-whole threadorall crthe bob- ..diametenonthe .tapcr of the product may be changed. or the r taper may be formed concomit- .ant ly .-with change-inane kind-of material of AVhiChthe-.braidis formed.

.bins :whichcarry. the strands thereof. Thus,-in the apparatus disclosed in my Patent No. 12,354,212;abobbin-may -be removed from a carmiertoremove .arthread and'simultaneously-ia Ifyin pp tus 0f i -e r mpreviously-removed-bobbin may be replaced upon of. the -.two bobbinson. each. carrier carriesa -..cotton strand.13,and.-the.other carries astrand "H of nylon, a braided patternrwill. be produced-when r all the bobbins :arein-placeiii-which the threads its carrier. This -rnay be the samecarrier 01:23 :different carrier. depending upon the total numrber-of carriers occupied by bobbins the threads of 'whiohienter .the braiding operation. 7 It will be wil1. pass over :2, under 2, over 2, un.der 2,-each gapparenl}, moreover; in the apparatusgdisclosedin :thrcad consisting oftwo. .sti1ands..one-of cotton andthe other of nylon. .If,.,however,all the nylon .bobbins are placed zonthevtables fiend-allthe cotton nbobbins are :allowed .to remain on their 1 Figs. 1 and *2. of the present application that bot-h bobbins :28 onptheirabobbin holders 2 I which are supported :on a given carrier ill may: be; removed at thesame time from this carrieran'd two. other ,spindles on .the respective carriers a -;-g5;b0bbin8 on their respective bobbin holders may product will. be .producedsinrwhich the patternis .stilLcver. 2, under-2,. over 2, under 2, but the .threadscomposing this. pattern each will consist of only one stran'dJlS, as shown. irrFig. 12, instead be placed upon the same carrier --l0-from which the: two-bobbins first mentioned were removed. -Such replacement of .a bobbin carrying a whole thread :orrof two, or. more bobbins carrying strands .of. two. .It isapparent that a braidedproduct of of a thread maybe made onanladJ-acent can cylindricalform thus maybe produced of-any desiredslength whichrwillsbe composed of the cot- ..ton strands, although. =it-will be. of less diameter hthan'when both cotton and nylon enter the braidrrier or one'from which-;the1thread or the. pair :Qfstrands venter theibraided pattern-yin the same manner as; the. threadrof. therremoved bobbin.

If the-materials; which are; on' the bobbins thus .edpattern. .If, now, allofthe bobbins carr -,;:'.5-.=:.i-nterchanged, whether .only one per carrier .or

thecottonstrands '13 are removed from-the carriers. l0. and are placed on the tables 46' and the rbobbins carrying thenylon strands H which pre- -viously were removed to thesetables are placed two or moregper carrier, ,are.;;of: diflerentrkind; or :characteristics, ,it 'will' be understood that the method of'the invention will eiiect the change Tin; the-material of .the vbraided .pattern :without .on-theirrespective; carriers the braided product N40 necessarily changingmhe diameter of the tubular .will. be. of. identical. pattern .with thatpreviously made of cotton strands but will be composed enstirely of.-nylon strandswas shown .at-the upper .part of. Fig. .12. ,Depending on the relative size of the nylon and cotton-strands :the diameter of the 4 .product willgbe the same or .diiferent in-the two .portions. Moreover, as: those bobbins 28 which .areremoved on theirbobbin holders to the .tables 46 .are. controlled by :theltension devices --:pro duct. Such .cbarnge'inv diameter-may be seecured, if desiredybycarrying strands ofthreads :which-areof different size or other. characteristicszon;.the:interchanged bobbins which would :.produce achange'jnthe bulk. of the product associated therewith, as above described, the vvtwwrlicrl carry strandswhichmake up the threads tightness ofthemesh of thebraidmay be.main- -.tained inboth portionspf the-length of the .braided product. Theinterchanging of bobbins, .-.of. course, again may be efiectedwhen desired .to .braida-portion. 0t cotton strands.

If desired, however,-insteadof removing all of the bobbins containing -.the --cotton -strands si- .multaneously with replacing otthe bobbins containing the nylon strands, especially as thismay involve stopping the machine; the-bobbins -contai-ning. the: cotton strands mayv be removed in successionrin a predetermined progressive order while the corresponding bobbins containing" the .-nylon strands are replaced i-rnsuccession on the respective carriers simultaneously with such re- $365 moval. Thus there will hey-produced over a certain length; of the tubular product aggradual change .from a braid composed entirely of cotton strands to one composed entirely: of-nylon= strands "or .sente'ring the braided'pattern also may be practiced .whentheinterchange is effected between :the :bobbins carryingthewhole thread or of the plurality of bobbins carrying a plurality of sstran'dsrmaking up 1 the whole thread.

:Allzsuch variations-maybe made'within the "scope. of the'invention and the method of pro- .-;ducing .'a braided product which utilizes a such variations. as wellaasfthe productitself and the yma'chinefrom producing this product are intend- :vice versa, the-intermediate portion containingw making up at least some. said threadsentering :strandsof 'bothkindszas shownxin-E'ig. 13. The product, -however,:may--be ofruniform braided .pattern and ofr uniform diameter.

Within the. scope of this aspect. of :the-rinventhe braiding operation.

2. The method ofbraiding a tubularproduct or varying diameter over a length thereof which 'comprisesbraiding a;plurality of threads at least .tion, -moreover,-.the methodpi jnterchangingbob- 75. SOmETiOf which -=are--made up of a plurality of ining up at least some of the threads entering the braiding operation, and holding said withheld strands under tension to control the braided mesh.

3. The method of braiding a tubular product .of varying diameter over a length thereof which comprises braiding a plurality of threads at least some of which are made up of a plurality of independent strands to form a tubular braided fabric, and changing the diameter of the braided product by changing the number of strands making up certain of said threads while also changing the number of threads entering into the braiding operation.

4. The method of braiding a tubular product of varying diameter over the length thereof and characterized by a uniform braided pattern which comprises braiding a plurality of threads each ,made up of a plurality of independent strands to form a tubular braided fabric, and changing ,the diameter of the braided product by changing the number of strands making up a thread which enters into the braiding operation without changing the number of threads entering into the braiding operation.

5. The method of braiding a tapered tubular product characterized by a uniform braided pattern which comprises braiding a plurality of threads each made up of a plurality of independent strands to form a tubular braided fabric, and progressively changing the diameter of the braided product by progressively changing the number of strands which enter into the braiding operation without changing the number of threads entering into the braiding operation.

6. The method of braiding a tubular product of varying diameter along its length and characterized by a uniform braided pattern which comprises braiding a plurality of threads each made up of a plurality of independent strands to form a tubular braided fabric, and changing the diameter of the braided product by withholding certain of said strands from entering into the braiding operation and maintaining at least some of said strands inside the tubular product Without changing the number of threads which enter the braiding operation.

7. The method of braiding a tubular product of'varying diameter along its length and characterized by a uniform braided pattern which comprises braiding a plurality of threads each made up of a plurality of independent strands to form a tubular braided fabric, and changing the diameter of the braided product by Withholding certain of said strands from entering into the braiding operation and maintaining at least some of said strands outside the tubular product without changing the number of threads which enter the braiding operation.

8. The method of braiding a tubular braided product of varying diameter along its length and characterized by a uniform braided pattern which comprises braiding a plurality of threads each made up of a plurality of independent strands to form a tubular braided fabric, and progressively changing the diameter of the tubular braided fabric by progressively withholding in step-like order some of the strands from entering into the braiding operation without changing the number of threads entering into the braiding operation.

9. The method of braiding a tubular braided 18 product of varying diameter along its length and characterized by a uniform braided pattern and substantially uniformly tightly braided throughout said length thereof which comprises braidinga plurality ofthreads each made up of a plurality of independent strands to form a tubular braided fabric, and changing the diameter of the tubular braided fabric by withholding some of the strands from entering into the braiding operation without changing the number of threads entering into the braiding operation, and maintaining under throughout the braiding operation all strands which are entering into or have into .the braiding operation. V

10. The method of braiding a tubular braided product of varying diameter along its length and characterized by a uniform braided pattern'and substantially uniformly tightly braided throughout the length thereof which comprises braiding a plurality of threads each made up of a plurality of independent strands to form a tubular braided fabric, progressively decreasing the diameter of said tubular braided fabric by progressively withholding in step-like order some ofthe strands from entering into the braiding operation and" thereafter progressively increasing the diameter of said tubular braided fabricby progressively returning the withheld strands in step-like order into the braiding operation, maintaining throughout the braiding operation the number of threads which enter into the braiding operation constant, and maintaining all of the strands which are currently entering into or have entered into the braiding operation under tension.

.11. The method of making braided catheter tubes having a cylindrical body portion and a tapered end portion and characterized by a uniform braided pattern and substantially uniformly' tightly braidedthroughout'the length thereof which comprises braiding a plurality of threads each'made up of a plurality of independent strands and sufficient in number to form the cylindrical tubular portion, progressively decreasing the diameter 'of the braided tube by progressively Withholding in step-like order some of the number of strands, from entering into the braiding operation 'to form the tapered tubular portion, thereafter progressively increasing the diameter of the braided tube by progressively returning to the braiding operation in step-like order the strands previously withheld to form a second tubular portion tapering in the opposite direction from the taper of said first mentioned tapered tubular portion, continuing the braiding operation with the threads including said returned strands to form a second cylindrical tubular portion, maintaining the number of threads which enter into the braiding pattern constant throughout the braiding of said cylindrical and tubular portions, and maintaining all of the threads which are currently entering into or have entered into the braiding operation under tension.

12. A braided tubular article having a cylindrical portion and a tapered portion adjacent each other in the length of the tube, said tapered portion being formed of threads which enter into the braid of the cylindrical portion, at least some of the threads of the braid pattern of said cylindrical portion being composed of a plurality of strands, at least some of said strands of said threads being excluded from the braid pattern in the tapered portion' while the other strands of tension of the entered 3 19 the same threads are continuous in the pattern in both the cylindrical and tapered portions.

13. A braided tuBiilar article having a cylindri'cal portion and a tapered portion adjacent each other in the length of the tiibe, said tapered portion being formed of threads which enter into the braid of the cylindrical portion; at least some of the threads of the braid pattern of said cylindri'cal portion being composed of a plurality of strands, at least some of the strands of said threads teirniiiating in the tapered portion while the other strands of the same threads are continuous in the cylindrical and tapered portions of said tube. I h

14. A braided tubular article having a cylindrical portion and a tapered portion adjacent each other the length of the tube, said tapered porti' n being mines of threads which enter into the braid oi the oylindricai portion, each of said threads of the braid pattern of said cylindrieal pet tion being composed of a plurality of strands, certain of the threads of said pattern having at leastone strandthereof but notall of its strands t'ermmatingin the tapered portion of the tube,

those strands which do not so terminate being eontinuous in both the cylindrical and tapered portions of said tube. 15. A braidedtubular article as defined in olairn 13 in which said terminating strands terminate at the exterior of said tapered portion.

1 6 A braided tubular article as defined in claim 12-, said strands which are excluded from the braided pattern passing inwardly to the space within the tube and being continuous therein from said cylindrical portion through the tapered portion of the tube.

17. A braided tubular article having a cylindrical portionand a tapered portion adjacent each other in the length of the tube, said tapered portion being formed of threads which enter into the braid of the cylindrical portion, at least some of the threads of the braid pattern of said cylindrical portion being composed of a plurality of strands, certain of said strands of said threads being excluded from the braid pattern in the tapered portion while the other str'andsof the saine threads are continuous in the pattern in both the cylindrical and tapered portions, the inesh of said braid pattern in both said portions being substantially iformly tight. 7 v

18. The method of braiding a tubular product ass sts which comprises braiding a plurality of threads to produce a given portion of the tubular product, at least some of said threads being composed of a plurality of strands, and withholding from entering the braiding operation at least soiiie of said strands of some or said threads which enter the braiding operation while maintaining other strands of said threads in the braiding operation to produce a portion of said tubular products'p'aced therealong from said given portion.

19 The method of braiding a tubular product which comprises braiding a plurality of threads to produce a given portion of the tubular prodnot; at least some of said threads being composed of a plurality of strands, and withholding from entering the braiding operation at least some of said strands of some of said threads which enter the braiding operation While maintaining other strands of said threads in the braiding operation t6 produce a portion of said tubular product spaced therealon'g from said given portion, said withheld strands being maintained under tension to control the braided mesh.

20. A braided tubular product having a portion in which threads enter into a predetermined braided pattern and individually are composed of a plurality of strands, and another portion spaced along said tubular product from said first portion in which at least some of said threads enter into the same predetermined braided pattern as in said first portion and respectively comprise at least one strand which entered said pattern in said first portion and from which at least another strand of the same thread is exchided in said second portion of said product.

NORMAN C. J ECKEL.

REFERENCES CITED The following references are of record in the The of this patent:

UNITED STATES PA'I'ENTS Number Name Date 4723,3 31 Lee r July 5, 1392 517,132 Wolff Mai. 27, 1894 530,873 Wolferts Dec. 11, 1894 "772,333 Chandler Oct. 13, 1904 958,372 Holzhe'y et 1 May 24, 1910 2,079,836 Brown et al. May 11, 1937 2,257,953 Haskell Oct. 7, 1941 2,287,200 Scott June 23, 1942 

